PR#6521: {Bytes,Char,String}.escaped are locale-dependent

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@15901 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

14 files changed, 89 insertions, 49 deletions

diff --git a/Changes b/Changes
index e0f16abf91..0b0b9596d0 100644
--- a/Changes
+++ b/Changes
@@ -76,6 +76,8 @@ Bug fixes:
 - PR#6171: Error message confusing when a type escapes its scope.
 - PR#6340: Incorrect handling of \r when processing "Windows" source files
   (Damien Doligez, report by David Allsopp)
+* PR#6521: String.escaped and Char.escaped are locale-dependent
+  (Damien Doligez, report by Jun Furuse)
 - PR#6526: ocamllex warning: unescaped newline in comment string
   (Damien Doligez, report by user 'dhekir')
 - PR#6560: Wrong failure message for {Int32,Int64,NativeInt}.of_string
diff --git a/boot/ocamlc b/boot/ocamlc
index 659084ba60..09984ea492 100755
--- a/boot/ocamlc
+++ b/boot/ocamlc
diff --git a/boot/ocamldep b/boot/ocamldep
index c5452cb0fd..5f36ae2460 100755
--- a/boot/ocamldep
+++ b/boot/ocamldep
diff --git a/boot/ocamllex b/boot/ocamllex
index 5d399cc609..da06c45cf0 100755
--- a/boot/ocamllex
+++ b/boot/ocamllex
diff --git a/byterun/str.c b/byterun/str.c
index e03dda6f53..5ad4e29419 100644
--- a/byterun/str.c
+++ b/byterun/str.c
@@ -21,9 +21,6 @@
 #include "caml/fail.h"
 #include "caml/mlvalues.h"
 #include "caml/misc.h"
-#ifdef HAS_LOCALE
-#include <locale.h>
-#endif
 
 /* returns a number of bytes (chars) */
 CAMLexport mlsize_t caml_string_length(value s)
@@ -279,21 +276,6 @@ CAMLprim value caml_fill_string(value s, value offset, value len, value init)
   return Val_unit;
 }
 
-CAMLprim value caml_is_printable(value chr)
-{
-  int c;
-
-#ifdef HAS_LOCALE
-  static int locale_is_set = 0;
-  if (! locale_is_set) {
-    setlocale(LC_CTYPE, "");
-    locale_is_set = 1;
-  }
-#endif
-  c = Int_val(chr);
-  return Val_bool(isprint(c));
-}
-
 CAMLprim value caml_bitvect_test(value bv, value n)
 {
   int pos = Int_val(n);
diff --git a/stdlib/bytes.ml b/stdlib/bytes.ml
index 193c3ceea1..32d4468c34 100644
--- a/stdlib/bytes.ml
+++ b/stdlib/bytes.ml
@@ -122,7 +122,6 @@ let cat s1 s2 =
   r
 ;;
 
-external is_printable: char -> bool = "caml_is_printable"
 external char_code: char -> int = "%identity"
 external char_chr: int -> char = "%identity"
 
@@ -151,7 +150,8 @@ let escaped s =
     n := !n +
       (match unsafe_get s i with
        | '"' | '\\' | '\n' | '\t' | '\r' | '\b' -> 2
-       | c -> if is_printable c then 1 else 4)
+       | ' ' .. '~' -> 1
+       | _ -> 4)
   done;
   if !n = length s then copy s else begin
     let s' = create !n in
@@ -168,19 +168,16 @@ let escaped s =
           unsafe_set s' !n '\\'; incr n; unsafe_set s' !n 'r'
       | '\b' ->
           unsafe_set s' !n '\\'; incr n; unsafe_set s' !n 'b'
+      | (' ' .. '~') as c -> unsafe_set s' !n c
       | c ->
-          if is_printable c then
-            unsafe_set s' !n c
-          else begin
-            let a = char_code c in
-            unsafe_set s' !n '\\';
-            incr n;
-            unsafe_set s' !n (char_chr (48 + a / 100));
-            incr n;
-            unsafe_set s' !n (char_chr (48 + (a / 10) mod 10));
-            incr n;
-            unsafe_set s' !n (char_chr (48 + a mod 10))
-          end
+          let a = char_code c in
+          unsafe_set s' !n '\\';
+          incr n;
+          unsafe_set s' !n (char_chr (48 + a / 100));
+          incr n;
+          unsafe_set s' !n (char_chr (48 + (a / 10) mod 10));
+          incr n;
+          unsafe_set s' !n (char_chr (48 + a mod 10));
       end;
       incr n
     done;
diff --git a/stdlib/bytes.mli b/stdlib/bytes.mli
index e9f713b912..621c619f78 100644
--- a/stdlib/bytes.mli
+++ b/stdlib/bytes.mli
@@ -179,6 +179,8 @@ val trim : bytes -> bytes
 val escaped : bytes -> bytes
 (** Return a copy of the argument, with special characters represented
     by escape sequences, following the lexical conventions of OCaml.
+    All characters outside the ASCII printable range (32..126) are
+    escaped, as well as backslash and double-quote.
 
     Raise [Invalid_argument] if the result is longer than
     {!Sys.max_string_length} bytes. *)
diff --git a/stdlib/char.ml b/stdlib/char.ml
index 56aa5d4924..58afbc7585 100644
--- a/stdlib/char.ml
+++ b/stdlib/char.ml
@@ -19,8 +19,6 @@ external unsafe_chr: int -> char = "%identity"
 let chr n =
   if n < 0 || n > 255 then invalid_arg "Char.chr" else unsafe_chr n
 
-external is_printable: char -> bool = "caml_is_printable"
-
 external string_create: int -> string = "caml_create_string"
 external string_unsafe_get : string -> int -> char = "%string_unsafe_get"
 external string_unsafe_set : string -> int -> char -> unit
@@ -33,12 +31,11 @@ let escaped = function
   | '\t' -> "\\t"
   | '\r' -> "\\r"
   | '\b' -> "\\b"
-  | c ->
-    if is_printable c then begin
+  | ' ' .. '~' as c ->
       let s = string_create 1 in
       string_unsafe_set s 0 c;
       s
-    end else begin
+  | c ->
       let n = code c in
       let s = string_create 4 in
       string_unsafe_set s 0 '\\';
@@ -46,7 +43,6 @@ let escaped = function
       string_unsafe_set s 2 (unsafe_chr (48 + (n / 10) mod 10));
       string_unsafe_set s 3 (unsafe_chr (48 + n mod 10));
       s
-    end
 
 let lowercase c =
   if (c >= 'A' && c <= 'Z')
diff --git a/stdlib/char.mli b/stdlib/char.mli
index 9eca9a297d..a5ad202114 100644
--- a/stdlib/char.mli
+++ b/stdlib/char.mli
@@ -23,8 +23,10 @@ val chr : int -> char
 
 val escaped : char -> string
 (** Return a string representing the given character,
-   with special characters escaped following the lexical conventions
-   of OCaml. *)
+    with special characters escaped following the lexical conventions
+    of OCaml.
+    All characters outside the ASCII printable range (32..126) are
+    escaped, as well as backslash, double-quote, and single-quote. *)
 
 val lowercase : char -> char
   [@@ocaml.deprecated "Use Char.lowercase_ascii instead."]
diff --git a/stdlib/string.ml b/stdlib/string.ml
index 0cea7acb74..ecb1be3c3b 100644
--- a/stdlib/string.ml
+++ b/stdlib/string.ml
@@ -73,8 +73,6 @@ let mapi f s =
    copy, but String.mli spells out some cases where we are not allowed
    to make a copy. *)
 
-external is_printable: char -> bool = "caml_is_printable"
-
 let is_space = function
   | ' ' | '\012' | '\n' | '\r' | '\t' -> true
   | _ -> false
@@ -90,7 +88,7 @@ let escaped s =
     if i >= length s then false else
       match unsafe_get s i with
       | '"' | '\\' | '\n' | '\t' | '\r' | '\b' -> true
-      | c when is_printable c -> needs_escape (i+1)
+      | ' ' .. '~' -> needs_escape (i+1)
       | _ -> true
   in
   if needs_escape 0 then
diff --git a/stdlib/string.mli b/stdlib/string.mli
index 82b26a3879..5b1233a6cf 100644
--- a/stdlib/string.mli
+++ b/stdlib/string.mli
@@ -158,13 +158,20 @@ val trim : string -> string
 
 val escaped : string -> string
 (** Return a copy of the argument, with special characters
-   represented by escape sequences, following the lexical
-   conventions of OCaml.  If there is no special
-   character in the argument, return the original string itself,
-   not a copy. Its inverse function is Scanf.unescaped.
+    represented by escape sequences, following the lexical
+    conventions of OCaml.
+    All characters outside the ASCII printable range (32..126) are
+    escaped, as well as backslash and double-quote.
 
-   Raise [Invalid_argument] if the result is longer than
-   {!Sys.max_string_length} bytes. *)
+    If there is no special character in the argument that needs
+    escaping, return the original string itself, not a copy.
+
+    Raise [Invalid_argument] if the result is longer than
+    {!Sys.max_string_length} bytes.
+
+    The function {!Scanf.unescaped} is a left inverse of [escaped],
+    i.e. [Scanf.unescaped (escaped s) = s] for any string [s] (unless
+    [escape s] fails). *)
 
 val index : string -> char -> int
 (** [String.index s c] returns the index of the first
diff --git a/testsuite/tests/lib-string/Makefile b/testsuite/tests/lib-string/Makefile
new file mode 100644
index 0000000000..6ae7266b0c
--- /dev/null
+++ b/testsuite/tests/lib-string/Makefile
@@ -0,0 +1,19 @@
+#########################################################################
+#                                                                       #
+#                                 OCaml                                 #
+#                                                                       #
+#                 Xavier Clerc, SED, INRIA Rocquencourt                 #
+#                                                                       #
+#   Copyright 2010 Institut National de Recherche en Informatique et    #
+#   en Automatique.  All rights reserved.  This file is distributed     #
+#   under the terms of the Q Public License version 1.0.                #
+#                                                                       #
+#########################################################################
+
+BASEDIR=../..
+LIBRARIES=str
+ADD_COMPFLAGS=-I $(OTOPDIR)/otherlibs/str
+LD_PATH=$(TOPDIR)/otherlibs/str
+
+include $(BASEDIR)/makefiles/Makefile.several
+include $(BASEDIR)/makefiles/Makefile.common
diff --git a/testsuite/tests/lib-string/test_string.ml b/testsuite/tests/lib-string/test_string.ml
new file mode 100644
index 0000000000..4ead7028be
--- /dev/null
+++ b/testsuite/tests/lib-string/test_string.ml
@@ -0,0 +1,35 @@
+(***********************************************************************)
+(*                                                                     *)
+(*                                OCaml                                *)
+(*                                                                     *)
+(*                Damien Doligez, Jane Street Capital                  *)
+(*                                                                     *)
+(*  Copyright 2015 Institut National de Recherche en Informatique et   *)
+(*  en Automatique.  All rights reserved.  This file is distributed    *)
+(*  under the terms of the Q Public License version 1.0.               *)
+(*                                                                     *)
+(***********************************************************************)
+
+let rec build_string f n accu =
+  if n <= 0
+    then String.concat "" accu
+    else build_string f (n-1) (f (n-1) :: accu)
+;;
+
+let char n = String.make 1 (Char.chr n);;
+
+let reference n =
+  if n = 8 then "\\b"
+  else if n = 9 then "\\t"
+  else if n = 10 then "\\n"
+  else if n = 13 then "\\r"
+  else if n = Char.code '"' then "\\\""
+  else if n = Char.code '\\' then "\\\\"
+  else if n < 32 || n > 126 then Printf.sprintf "\\%03d" n
+  else char n
+;;
+
+let raw_string = build_string char 256 [];;
+let ref_string = build_string reference 256 [];;
+
+if String.escaped raw_string <> ref_string then failwith "test:String.escaped";;
diff --git a/testsuite/tests/lib-string/test_string.reference b/testsuite/tests/lib-string/test_string.reference
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/testsuite/tests/lib-string/test_string.reference